In recent years, organic-inorganic hybrid perovskite solar cells (PSCs) have made great progress and encouraged researchers to develop and test many architectures. In this paper, the effect of using NiO@GeSe core-shell nanorod (NR) array based on the light trapping mechanism on the absorption, generation, collection, and transfer of carriers and finally the overall efficiency of a PSC is investigated using a three-dimensional (3D) finite element method (FEM). By choosing NiO as the core and GeSe as the shell in the core-shell form of NiO@GeSe, the active layer absorption was increased relative to the planar structure. This core-shell structure causes the reduction of carrier recombination within the PSC. Under the normal-angle sunlight (AM1.5G), the PSC containing light-trapping architecture showed a good increase in the light absorption, carrier generation and short-circuit current density (J(sc)). The simulation results show a high dependence of the device performance on the height and material of NRs. Significantly, an optimum height of 120 nm was achieved for NRs in PSC with J(sc) of 24.24 mA/cm(2), the open-circuit voltage (V-oc) of 0.99 V and the efficiency of 20.29%. This strategy opens a new horizon in the development of PSCs with the practical applications and high efficiency.